var mongoose = require("mongoose");
var DB_URL = 'mongodb://localhost:27017/demo';

// 连接
mongoose.connect(DB_URL);

// 连接成功
mongoose.connection.on('connected', function() {
    console.log(`Mongoose connected on: ${DB_URL}`);
});

// 连接异常
mongoose.connection.on('error', function(err) {
    console.log(`Mongoose connected error: ${err}`);
});

// 连接断开
mongoose.connection.on('disconnected', function() {
    console.log('Mongoose connection disconnected');
});

module.exports = mongoose;